# zip & unzip
letters = ["a", "b", "c", "d"]
numbers = (1, 2, 3)
mapping = dict(zip(letters, numbers))
print(mapping)
merged = zip(letters, numbers)
origin = zip(*merged)
for e in origin:
    print(e)

# enum
l = [1, 2, 3]
for i, e in enumerate(l):
    print(f"index={i}, element={e}")
